Index: media/audio/mac/audio_low_latency_input_mac.h |
=================================================================== |
--- media/audio/mac/audio_low_latency_input_mac.h (revision 104447) |
+++ media/audio/mac/audio_low_latency_input_mac.h (working copy) |
@@ -27,6 +27,11 @@ |
// input device and then use the same rate when creating this object. |
// Use AUAudioInputStream::HardwareSampleRate() to retrieve the sample rate. |
// - Calling Close() also leads to self destruction. |
+// - The latency consists of two parts: |
+// 1, Hardware latency, which includes Audio Unit latency, audio device |
+// latency and audio stream latency; |
+// 2, The delay between now and the scheduled time stamp that tells when the |
+// data we are providing is going to reach the hardware. |
// |
#ifndef MEDIA_AUDIO_MAC_AUDIO_LOW_LATENCY_INPUT_MAC_H_ |
#define MEDIA_AUDIO_MAC_AUDIO_LOW_LATENCY_INPUT_MAC_H_ |
@@ -73,8 +78,15 @@ |
AudioBufferList* io_data); |
// Pushes recorded data to consumer of the input audio stream. |
- OSStatus Provide(UInt32 number_of_frames, AudioBufferList* io_data); |
+ OSStatus Provide(UInt32 number_of_frames, AudioBufferList* io_data, |
+ const AudioTimeStamp* time_stamp); |
+ // Get the fixed capture hardware latency and store it during initialization. |
+ void StoreHardwareLatency(); |
+ |
+ // Updates the current capture delay value. |
+ void UpdateCaptureLatency(const AudioTimeStamp* input_time_stamp); |
+ |
// Issues the OnError() callback to the |sink_|. |
void HandleError(OSStatus err); |
@@ -96,6 +108,9 @@ |
// The AUHAL also enables selection of non default devices. |
AudioUnit audio_unit_; |
+ // The UID refers to the current input audio device. |
+ AudioDeviceID input_device_id_; |
+ |
// Provides a mechanism for encapsulating one or more buffers of audio data. |
AudioBufferList audio_buffer_list_; |
@@ -106,6 +121,12 @@ |
// True after successfull Start(), false after successful Stop(). |
bool started_; |
+ // Fixed capture hardware latency in frames. |
+ double hardware_latency_frames_; |
scherkus (not reviewing)
2011/10/19 16:35:15
frames are typically integers -- any reason why we
|
+ |
+ // Current capture latency in frames. |
+ double capture_latency_frames_; |
+ |
DISALLOW_COPY_AND_ASSIGN(AUAudioInputStream); |
}; |